1. Technical Field
The present disclosure described herein relates generally to wireless communications and more particularly to error correction in wireless communication systems.
2. Description of Related Art
Communication systems are known to support wireless and wire line communications between wireless and/or wire line communication devices. The communication systems range from national and/or international mobile/handheld systems to the point-to-point gaming, in-home wireless networks, audio, video wireless devices. Communication systems typically operate in accordance with one or more communication standards such as long-term evolution (LTE).
User equipment (UE), such as a mobile phone operating within a communication system, will often experience reduced transmission quality at the edge of a communications cell, especially in poor radio conditions (e.g., high interference, low transmission power, etc.). As the UE transmits to a cell node, such as an E-UTRAN Node B (eNB), which may include a base transceiver station (BTS-in GSM networks), error correction techniques are used to improve a likelihood of success. One known error correction technique is a hybrid automatic repeat request (HARQ), which includes various methods of repeating the transmission until the receiving node can decode the transmission. HARQ is a combination of high-rate forward error-correcting coding and ARQ (Auto Repeat Request) error-control. Receivers detecting a corrupted message will request a new message from the sender. In HARQ, the original data is encoded with a forward error correction (FEC) code, and the parity bits are either immediately sent along with the message or only transmitted upon request when a receiver detects an erroneous message.
One variation of HARQ, used in LTE, is incremental redundancy HARQ. When the cell node detects erroneous data, it holds it for use with future repeated transmissions. The UE will transmit the same data again with a different set of coded bits. The previously received erroneous data will be combined at the node with newly received data to improve the chances of successfully decoding the data. This will repeat until the receiver is able to decode the data.